TORONTO — The Red Sox had a chance to reset their wayward season against the Toronto Blue Jays Sunday. The situation, the opponent, everything was right.

Jon Lester was on the mound against R.A. Dickey, a pitcher the Sox hit hard last year. A victory would have meant a series sweep and getting back to .500 before a day off and the start of an eight-game homestand Tuesday.

True enough. But there are troubling tendencies all around, including an inability to give their best pitcher any support.

Lester has a 3.10 earned run average after six starts but is 2-4 thanks, in part, to his teammates. The Sox have scored 12 runs in those games and Sunday were held to six hits, five of them singles. They also failed to draw a walk.

It was the seventh time already this season the Sox were held to two or fewer runs.

“I don’t get to hit. If I did, it would probably be worse,” Lester said. “I know these guys are busting their butt. Dickey threw the ball really well today.”

Lester allowed a solo home run by Brett Lawrie in the second inning and a two-out RBI double by Melky Cabrera in the third inning, an opposite-field grounder that went down the line in right field.

Lester then retired 10 in a row before giving up two runs in the seventh inning.

Edwin Encarnacion led off the inning with a line drive to left field. The ball went to the wall as Grady Sizemore was unable to cut it off. Lawrie followed with a line drive just over the head of Will Middlebrooks at third base and Toronto had a 3-1 lead.

Lawrie went to third on a fly ball to deep center. With the infield in, Moises Sierra tapped a ball to Lester’s right. The pitcher, a poor fielder, might have had a play at the plate but couldn’t get the ball out of his glove in time and had to go to first, Lawrie scoring.

Lester didn’t think he had a chance at Lawrie regardless.

“I didn’t have a play even if I field it cleanly. I couldn’t square my shoulders. I couldn’t do anything,” he said.

Lester allowed four runs on five hits and struck out seven without a walk.

“Thought I threw the ball well,” he said. “Couple of mistakes and they made me pay for it later in the game. I let it get out of hand there in the seventh. I felt like I threw the ball better than the four runs up there.”

Poor defense cost the Red Sox again in the eighth inning. With one out and Jose Reyes on first after a single off lefthander Andrew Miller, Cabrera popped up behind the plate. The usually reliable David Ross dropped the ball and was charged with an error.

Cabrera then dropped a single into right field and Reyes went to third. Jose Bautista followed with a grounder up the middle. Xander Bogaerts had little chance at Bautista but fumbled the ball and didn’t get a force at second, Reyes scoring.

Encarnacion then hammered a two-run double to center off Burke Badenhop.

The Red Sox have given up 18 unearned runs in their 26 games.

“The popup today leads to an added out and what we’ve seen is when that added out comes we’re looking at a crooked number on the board,” manager John Farrell said.

Dickey faced the Red Sox twice last season and allowed 13 runs on 16 hits — four of them home runs — over 12⅔ innings. But the knuckleballer was strong this time, allowing one run on five hits over 6⅓ innings. Dickey worked fast, threw strikes, and cruised after giving up a run in the second inning.

When Dickey was on the mound, the Red Sox grounded into six outs, popped up five times, and struck out six times. Hard contact was at a minimum.

“He threw a number of first-pitch fastballs to get ahead and get a strike and then go to his knuckleball and various speeds off that,” Farrell said.

The run came in the second inning when singles by Jonny Gomes, Bogaerts, and Bradley gave the Red Sox a 1-0 lead. They didn’t get a runner in scoring position again until the seventh inning.

Middlebrooks was hit by a pitch and took third on a double to left field by Bogaerts. Toronto manager John Gibbons changed styles, bringing in Steve Delabar, a righthander with a 95-mile-per-hour fastball.

Bradley got ahead, 2 and 0, took a strike, then fouled to third base. Ross hit the ball well but it was caught in deep center.

The Red Sox were 1 for 4 with runners in scoring position and are hitting .218 in such situations this season.